What Is ERW And SAW Steel Pipe?

What is ERW steel pipe?
ERW steel pipe (resistance welded steel pipe) uses the skin effect and proximity effect of high-frequency current to heat and melt the edges of the hot-rolled coil formed by the forming machine, and then weld the pressing and extrusion rollers under pressure to achieve production. ERW has the characteristics of high efficiency, low cost, material saving, and easy automation. Widely used in aviation, aerospace, energy, electronics, automobiles, light industry and other industrial sectors. It is an important link in the welding process.
Electric resistance welded steel pipes are divided into two forms: AC welded steel pipes and DC welded steel pipes. AC welding is divided into low frequency welding, medium frequency welding, super medium frequency welding and high frequency welding according to frequency. High-frequency welding is mainly used for the production of thin-walled steel pipes or ordinary-walled steel pipes. High-frequency welding is divided into contact welding and induction welding. Small diameter steel pipes generally use DC welding.
Therefore, in summary, high-frequency welded pipes belong to ERW welded pipes, which are a type of ERW welded pipes produced using high-frequency welding processes. ERW straight seam welded pipe is a steel pipe with advanced product performance, leading quality and relatively economical performance in the field of oil and gas storage and transportation.

What is submerged arc welded steel pipe?
SAW steel pipe (submerged arc welded steel pipe) can be divided into straight seam submerged arc welded steel pipe (LSAW steel pipe) and spiral submerged arc welded steel pipe (SSAW steel pipe). SAW is a manufacturing process that utilizes submerged arc welding of steel, which produces a high current density that prevents the flux layer from quickly losing heat and concentrating it in the weld area. A commonly used standard is API 5L.
Submerged arc welded pipes have the characteristics of high weld quality, high production efficiency, and smoke-free arc ignition. Submerged arc welded pipes are widely used in pressure vessels, pipeline manufacturing, construction beams, low-pressure fluids, and steel structure projects.

ERW steel pipe VS SAW steel pipe
Carbon steel welded pipes can be divided into three types according to the forming method of the weld: longitudinal submerged arc welded steel pipes, spiral welded steel pipes, and high-frequency straight seam welded steel pipes (resistance welded steel pipes). During the manufacturing process, we can see that ERW steel pipes and SAW steel pipes (LSAW, SSAW) have completely different forming and welding methods.